The development of haemoglobin preparations for various indications

Area of Science:

• Biochemistry
• Hematology
• Pharmacology

Background:

• Human erythrocyte haemoglobin solutions were investigated for therapeutic applications.
• Initial preparations exhibited high oxygen affinity and short intravascular half-life, limiting efficacy.
• Challenges included optimizing oxygen release and extending circulation persistence.

Purpose of the Study:

• To review investigational concepts and experimental results of haemoglobin solutions over a decade.
• To address limitations of unmodified haemoglobin, specifically high oxygen affinity and short half-life.
• To explore chemical modifications for enhanced therapeutic properties and clinical utility.

Main Methods:

• Chemical modification of free haemoglobin using pyridoxal-phosphate (HbPP).
• Increasing molecular size of HbPP via intermolecular cross-linkage (HbHbPP) to prolong intravascular efficiency.
• Review of research spanning ten years on haemoglobin solution development and testing.

Main Results:

• Attempts to raise 2,3-diphospho-glycerate (Hb-DPG) levels partially compensated for high oxygen affinity.
• Pyridoxal-phosphate modification (HbPP) demonstrated significant interest, particularly for myocardial perfusion.
• Cross-linking modified haemoglobin (HbHbPP) successfully increased molecular size, enhancing intravascular persistence.

Conclusions:

• Chemical modification of haemoglobin offers a viable strategy to overcome limitations of native solutions.
• HbPP and HbHbPP represent advanced haemoglobin-based oxygen carriers with potential clinical applications.
• Further investigation into the clinical utility of modified haemoglobin preparations is warranted.